Gas turbine engines for aircraft require a compressor in a gas turbine. Light weight of the gas turbine engine is important. Usually the compressor includes a low pressure compressor and a high pressure compressor. Low temperature exists in a low pressure compressor making it possible to use many composite materials.
U.S. Pat. No. 4,655,682 issued Apr. 7, 1987 to Cleon V. Kunz and Dennis H. Jones shows a composite inner shroud for low pressure compressor. The inner ends of the compressor vanes are potted within pockets in this inner shroud. A support structure to which the shroud is secured on its shroud edge carries on its inside surface an abradable seal. Knife edges on the turbine rotor interact with the abradable seal to form a flow restriction, sealing against bypass airflow.
When the compressor rotor is radially remote from the airflow path a deeper pocket is used than would be required for bond strength and vibration damping. This pocket is filled with potting compound, thereby adding weight to the compressor. This remote location tends to exist at the axial extreme of the compressor.
There the shroud is adhesively bonded to the support structure, this occurring along contacting surfaces. While substantial surface area is achieved for the bonding, there is a potential of peeling apart of the two surfaces upon failure at one location.